Various track type vehicles, such as crawler tractors, military tracked vehicles, and the like, include a pair of endless tracks, one mounted on each side thereof to propel the vehicle both forwardly and rearwardly, with steering effected by forcible track skewing. Each of the tracks is mounted on the vehicle's frame being entrained about the usual idler wheel and driven by toothed sprocket wheels from the final drive line enclosed in a housing also mounted in the frame.
During certain conditions particularly when operating in moist soil the tracks tend to pickup the mud, snow, ice and other abrasive foreign material which tends to impact between the track assembly and the housing. In vehicles whose sprocket wheels have no self clearing apertures or other scraper means, this mud and foreign material not only increases tractive effort, and adds undue wear, but also tends to build up and throw off or break the track, particularly when the aforementioned skewing action is involved.
Among the prior art are various different forms of scrapers adapted for tractors and other tracked vehicles to try to mitigate or solve the same general problem for their particular vehicle needs. Some of the more relevant prior U.S. Patents include U.S. Pat. No. 2,560,307 to Slemmons, which is directed to specific scraper bar means embodying a projecting nib to register within a general V-shape groove of the band and pulley drive system. U.S. Pat. No. 2,637,603 to Cartlidge involves a more complex two piece stripper ring which completely surrounds the central portion of its drive hub. U.S. Pat. No. 3,976,337 is directed to yet another different type of combined scraper/striker bar for cleaning and preventing debris buildup of its tracked vehicle. The cantilevered single blade form of angularly disposed striker bar is specifically different from the other patented devices and the present scraper, and extends downwardly relative to the rotational axis of its drive sprocket or annular member. U.S. Pat. No. 4,134,622 to Krolak et al. teaches still different generally U-shape scrapers which are differently disposed and the first of which removes foreign material from the chain and the second of which removes foreign material from the track. Lastly, U.S. Pat. No. 4,531,787 to Hart et al. is for a still different inverted V-shaped semi-flexible elastomeric deflector.
While the various prior art patents may satisfy the needs of their particular vehicles, the present scraper is directed to a simplified basically three-part scraper assembly uniquely needed to remove and avoid debris buildup from the inner half portions of the type of drive sprocket hubs which do not lend themselves to the provision of self-cleaning apertures, which apertures are provided in its outer half counterpart particularly for many military type vehicles, as will be be described in more detail hereinafter. The types of vehicles on which the present scraper attachment has been found to work very successfully, include various military tracked vehicles which use the M88chassis, including an M-88 tank retriever vehicle, the counter obstacle vehicle, and the M-60 tank, among others. This particular chassis is provided with several tie-down eyelets same of which are particularly useful for attachment by one form of the scraper assembly of this invention with a separable support portion of said novel scraper bar assembly being adapted to be welded thereto.